using System;
using System.Collections.Generic;
using System.Linq.Expressions;
using Tanshu.Accounts.Entities;
using Tanshu.Common.Helpers;
using NHibernate;
using System.Linq;
using Tanshu.Accounts.Contracts;

namespace Tanshu.Accounts.Repository
{
    public class VoucherBI : UnitOfWork<Voucher>
    {
        public new Guid Insert(Voucher voucher)
        {
            _session.Save(voucher);
            Kot addedKot = null;
            foreach (var item in voucher.Kots.Where(item => item.KotID == Guid.Empty))
            {
                addedKot = item;
                item.Voucher = voucher;
                item.Printed = true;
                item.Table = voucher.Table;
                item.User = voucher.User;
                UpdateBillType(voucher);
                _session.Save(item);
                foreach (var inv in item.Inventories)
                {
                    inv.Kot = item;
                    _session.Save(inv);
                    foreach (var modifier in inv.InventoryModifier)
                    {
                        modifier.Inventory = inv;
                        _session.Save(modifier);
                    }
                }
            }
            var amount = -1 * voucher.Kots.Sum(x => x.Inventories.Sum(y => y.Amount));
            VoucherSettlementBI.UpdateSettlements(voucher.Settlements, amount);
            foreach (var settlement in voucher.Settlements.Where(x => x.Amount != 0 || x.Settled == SettleOption.Amount))
            {
                settlement.Voucher = voucher;
                _session.Save(settlement);
            }
            return addedKot == null ? Guid.Empty : addedKot.KotID;
        }
        public Guid Insert(Voucher voucher, bool updateTable)
        {
            var kotID = Insert(voucher);
            if (updateTable)
            {
                var table = _session.QueryOver<FoodTable>().Where(x => x.FoodTableID == voucher.Table.FoodTableID).SingleOrDefault();
                if (table.VoucherID.HasValue)
                    throw new ValidationException("A bill exists on this table, cannot overwrite");
                var status = !voucher.Printed ? "running" : "printed";
                table.VoucherID = voucher.VoucherID;
                table.Status = status;
                _session.Update(table);
            }
            return kotID;
        }
        public new Guid? Update(Voucher voucher)
        {
            _session.Update(voucher);

            Kot addedKot = null;
            foreach (var item in voucher.Kots.Where(item => item.KotID == Guid.Empty))
            {
                addedKot = item;
                item.Voucher = voucher;
                item.Printed = true;
                item.Table = voucher.Table;
                item.User = voucher.User;
                _session.Save(item);
                foreach (var inv in item.Inventories)
                {
                    inv.Kot = item;
                    _session.Save(inv);
                    foreach (var modifier in inv.InventoryModifier)
                    {
                        modifier.Inventory = inv;
                        _session.Save(modifier);
                    }
                }
            }
            UpdateBillType(voucher);
            var amount = -1 * voucher.Kots.Sum(x => x.Inventories.Sum(y => y.Amount));
            VoucherSettlementBI.UpdateSettlements(voucher.Settlements, amount);
            foreach (var settlement in voucher.Settlements)
            {
                settlement.Voucher = voucher;
                if (settlement.Amount == 0 && settlement.Settled != SettleOption.Amount)
                {
                    if (settlement.VoucherSettlementID != Guid.Empty)
                        _session.Delete(settlement);
                }
                else if (settlement.VoucherSettlementID == Guid.Empty)
                    _session.Save(settlement);
                else
                    _session.Update(settlement);
            }
            return addedKot == null ? (Guid?)null : addedKot.KotID;
        }
        public Guid? Update(Voucher voucher, bool updateTable)
        {
            var kotID = Update(voucher);
            if (updateTable)
            {
                var table = _session.QueryOver<FoodTable>().Where(x => x.FoodTableID == voucher.Table.FoodTableID).SingleOrDefault();
                var status = !voucher.Printed ? "running" : "printed";
                table.VoucherID = voucher.VoucherID;
                table.Status = status;
                _session.Update(table);
            }
            return kotID;
        }
        public new Voucher Get(Expression<Func<Voucher, bool>> query)
        {
            var voucher = _session.QueryOver<Voucher>()
                .Where(query)
                .SingleOrDefault();
            NHibernateUtil.Initialize(voucher.Customer);
            NHibernateUtil.Initialize(voucher.Waiter);
            NHibernateUtil.Initialize(voucher.User);
            NHibernateUtil.Initialize(voucher.Table);
            foreach (var kot in voucher.Kots)
            {
                NHibernateUtil.Initialize(kot);
                NHibernateUtil.Initialize(kot.User);
                foreach (var item in kot.Inventories)
                {
                    NHibernateUtil.Initialize(item);
                    NHibernateUtil.Initialize(item.Product);
                    NHibernateUtil.Initialize(item.Product.ProductGroup);
                    foreach (var inmod in item.InventoryModifier)
                        NHibernateUtil.Initialize(inmod.Modifier);
                }
            }
            foreach (var item in voucher.Settlements)
                NHibernateUtil.Initialize(item);
            return voucher;
        }
        public void VoidBill(Guid voucherID, string reason, bool updateTable)
        {
            var voucher = _session.Get<Voucher>(voucherID);
            voucher.Void = true;
            voucher.VoidReason = reason;
            _session.Update(voucher);

            if (updateTable)
            {
                var table = _session.QueryOver<FoodTable>().Where(x => x.FoodTableID == voucher.Table.FoodTableID).SingleOrDefault();
                table.VoucherID = null;
                table.Status = null;
                _session.Update(table);
            }
        }

        public Guid MergeKot(Guid kotID, string tableName)
        {
            var kot = _session.Get<Kot>(kotID);
            var oldVoucher = kot.Voucher;
            var table = _session.QueryOver<FoodTable>().Where(x => x.Name == tableName).SingleOrDefault();
            var newVoucher = _session.Get<Voucher>(table.VoucherID);

            oldVoucher.Kots.Remove(kot);
            kot.Voucher = newVoucher;
            newVoucher.Kots.Add(kot);

            _session.Update(kot);
            _session.Update(oldVoucher);
            _session.Update(newVoucher);
            return newVoucher.VoucherID;
        }

        public Guid MergeTables(Guid voucherID, string tableName)
        {
            var newTable = _session.QueryOver<FoodTable>().Where(x => x.Name == tableName).SingleOrDefault();
            var newVoucher = _session.Get<Voucher>(newTable.VoucherID);
            var oldVoucher = _session.Get<Voucher>(voucherID);
            for (var i = oldVoucher.Kots.Count - 1; i >= 0; i--)
            {
                var kot = oldVoucher.Kots[i];
                oldVoucher.Kots.Remove(kot);
                kot.Voucher = newVoucher;
                newVoucher.Kots.Add(kot);
                _session.Update(kot);
            }
            _session.Update(newVoucher);


            var oldTable = _session.QueryOver<FoodTable>().Where(x => x.FoodTableID == oldVoucher.Table.FoodTableID).SingleOrDefault();
            foreach (var item in oldVoucher.Settlements)
            {
                _session.Delete(item);
            }
            _session.Delete(oldVoucher);
            oldTable.VoucherID = null;
            oldTable.Status = null;
            _session.Update(oldTable);
            return newVoucher.VoucherID;
        }
        private static void UpdateBillType(Voucher voucher)
        {
            switch (voucher.VoucherType)
            {
                case VoucherType.Regular:
                    break;
                case VoucherType.NoCharge:
                    foreach (var item in voucher.Kots.SelectMany(kot => kot.Inventories))
                    {
                        item.ServiceCharge = 0;
                        item.ServiceTaxRate = 0;
                        item.VatRate = 0;
                    }
                    break;
                case VoucherType.TakeAway:
                    foreach (var item in voucher.Kots.SelectMany(kot => kot.Inventories))
                    {
                        item.ServiceCharge = 0;
                        item.ServiceTaxRate = 0;
                    }
                    break;
                case VoucherType.Staff:
                    foreach (var item in voucher.Kots.SelectMany(kot => kot.Inventories))
                    {
                        item.ServiceCharge = 0;
                        item.ServiceTaxRate = 0;
                        item.VatRate = 0;
                    }
                    break;
            }
        }

        public Guid MoveKot(Guid kotID, Guid tableID)
        {
            var kot = _session.Get<Kot>(kotID);
            var oldVoucher = _session.Get<Voucher>(kot.Voucher.VoucherID);
            var table = _session.QueryOver<FoodTable>().Where(x => x.FoodTableID == tableID).SingleOrDefault();
            var newVoucher = new Voucher(Session.User, oldVoucher.Customer, table, oldVoucher.Waiter, false, false, "");
            Insert(newVoucher);
            table.VoucherID = newVoucher.VoucherID;
            table.Status = "running";
            _session.Update(table);


            oldVoucher.Kots.Remove(kot);
            kot.Voucher = newVoucher;
            newVoucher.Kots.Add(kot);

            _session.Update(kot);
            _session.Update(oldVoucher);
            _session.Update(newVoucher);

            return newVoucher.VoucherID;
        }

        public void SplitBill(Guid oldVoucherID, Voucher first, Voucher second)
        {
            var oldVoucher = _session.Get<Voucher>(oldVoucherID);
            oldVoucher.User = Session.User;
            oldVoucher.Void = true;
            oldVoucher.VoidReason = "Bill Split";

            Insert(first);
            Insert(second);
            Update(oldVoucher);

            var status = oldVoucher.Printed ? "printed" : "running";

            var tableFirst = _session.QueryOver<FoodTable>().Where(x => x.FoodTableID == first.Table.FoodTableID).SingleOrDefault();
            if (tableFirst.VoucherID.HasValue)
                throw new ValidationException("A bill exists on this table, cannot overwrite");
            tableFirst.VoucherID = first.VoucherID;
            tableFirst.Status = status;
            _session.Update(tableFirst);

            var tableSecond = _session.QueryOver<FoodTable>().Where(x => x.FoodTableID == second.Table.FoodTableID).SingleOrDefault();
            tableSecond.VoucherID = second.VoucherID;
            tableSecond.Status = status;
            _session.Update(tableFirst);
        }

        public void DiscountPrintedBill(Guid oldVoucherID, Voucher newVoucher)
        {
            var oldVoucher = _session.Get<Voucher>(oldVoucherID);
            oldVoucher.User = Session.User;
            oldVoucher.Void = true;
            oldVoucher.VoidReason = string.Format("Bill Discounted / Changed. New Bill ID is {0}", newVoucher.BillID);

            Insert(newVoucher);
            Update(oldVoucher);

            var table = _session.QueryOver<FoodTable>().Where(x => x.FoodTableID == oldVoucher.Table.FoodTableID).SingleOrDefault();
            table.VoucherID = newVoucher.VoucherID;
            table.Status = "printed";
            _session.Update(table);
        }
        public Guid Move(Guid oldTableID, Guid newTableID)
        {
            var oldTable = _session.QueryOver<FoodTable>().Where(x => x.FoodTableID == oldTableID).SingleOrDefault();
            var newTable = _session.QueryOver<FoodTable>().Where(x => x.FoodTableID == newTableID).SingleOrDefault();
            var voucher = _session.Get<Voucher>(oldTable.VoucherID);

            newTable.Status = oldTable.Status;
            newTable.VoucherID = oldTable.VoucherID;

            oldTable.Status = null;
            oldTable.VoucherID = null;

            voucher.Table = newTable;

            _session.Update(newTable);
            _session.Update(oldTable);
            _session.Update(voucher);
            return voucher.VoucherID;
        }
    }
}